Chevy 5.0 into Mk1 capri.

kiwicar · Post by **kiwicar** » Tue Jan 15, 2008 12:41 pm

If this is a 302 small block not a 305 then you have a very different beast and quite a rare find. the 302 is a 4" bore by 3" stroke high rev Transam racing homologation special (i think made for about a year). It takes 350 chevy pistons, can take much longer connecting rods, 350 heads. I think all the bottom end journal dimentions are 350 not 305, If the heads are original to the 75 block then they will be top quality factory castings.
If it is a 302 (check the bore is it 4" not 3.76 whatever) then it is a very good base for a real fun engine. Does it have 4 bolt mains? if not do you want a set? If you decide to rebuild it as a performance engine I'll send you a pair of iron vortec heads if you want, for the cost of postage (they need a rebuild but are good for 400BHP rebuilt and 420 Ported). Sorry got excited there

can you measure it up and let me know.

Best regards
Mike

Alley Kat · Post by **Alley Kat** » Tue Jan 15, 2008 12:45 pm

LOL, that bit picked me up too, I'm guessing it's a translation of the 5 litres not the actual designation/ci. If its that era it'll be a 305.

Did see a 302 a year or two go for quite impressive £s...

Raw · Post by **Raw** » Tue Jan 15, 2008 1:03 pm

My brain is racing at 1000mph....!

The cleaner just threw out my sheet with the dimensions...

I will be going at the engine again tonight. I will take off the sump and will look at the journals and get the bore and stroke. I must find out also what cam is in it.

This is a total learning curve for me, with the Chevy stuff.

Thanks for the help.

kiwicar · Post by **kiwicar** » Tue Jan 15, 2008 1:41 pm

Now I'm a bit confused, reading around the 302 was made in '67 and '68 (might be 69 aswell) the 305 was '76 onward I can't find that casting number on the usual google lists. If it is a '69 302 it will have 4 bolt mains, in any case it will have a 4 inch bore and a 3 inch stroke. The quickest thing to do is measure it.
Sorry dont want to get you hopes up too high but a 302 is a find!
Mike

kiwicar · Post by **kiwicar** » Tue Jan 15, 2008 2:03 pm

Might want to read this.
http://www.holisticpage.com/camaro/camaros/302.htm
Mike

Alley Kat · Post by **Alley Kat** » Tue Jan 15, 2008 2:12 pm

The numbers can be hard to get right, off the heads and block, at least mine were with certain digits. Had to try a few 'possibles', but mortec.com has about everything on there. Try srching on parts of numbers that you know are spot on.

Raw · Post by **Raw** » Wed Jan 16, 2008 9:32 am

The bubble burst last night when I investigate further.

Bore 95mm or 3.74inch
Stroke 88.9mm or 3.5inch
Still an over square but not what I was expecting/wishing for.

The crankshaft sits on 5 main bearings.

Mike, I not 100% sure what you mean by 4 bolt mains? Can you please explain for the uneducated?

Also, no baffles in the oil pan. Just as well that I took it off. There was porridge in the sump. Guess this engine hasn't been run in ages.

I guess this means that I have a 305 block so....?

Alley Kat · Post by **Alley Kat** » Wed Jan 16, 2008 10:07 am

It's a 305 then.
4-bolt mains is where 4-bolts are used to locate the main bearing caps, instead of the normal 2 per cap. Don't think there were any 4-bolt 305s.

Find out about the heads. Some 70s SBC heads, 350s anyway, were particularly prone to cracking but I don't think the number was one you mentioned. I had a set, they were fine, but worth f-all to sell.

Some 305s start out at stock as I said before, with all the smog crap around 120bhp mark, but my mate/client engine bloke reckons 300bhp is do-able and the result is a nice revvy engine. Chevy parts are so cheap and plentiful too.

kiwicar · Post by **kiwicar** » Wed Jan 16, 2008 9:21 pm

Don't worry too much about it, as Alley Kat says they make a good revy engine. If you had had a 302 you would have had to think what best to do with it a good one with good standard bores and the right numbers and 4 bolt mains would be worth quit big cash, someone restoring a formula 5000 or a 80's can-am revival would pay big cash for one

Right a 305 is a good base engine, to start with, 350 main bearing sizes so a wide choice of cheep cranks if you need one, wide choice of all bits infact. Heads wise you want to stick with 1.9" inlets as the 2.02 valve heads tend to shroud the valves too much.
The offer is open on the bits if you want, the block can be converted to 4 bolt mains with a set of caps (I can post a set to you if you want them) and you get whoever is machining your block to drill the extra holes for you and line bore the mains for you. It is worth doing if you are having the maines line bored but probably not worth it if your budget it too tight for a full machine job.
I would consider carfully if you have the cash for a set of ally heads, Air Flow Research 180 cc inlet tract heads have flow charictoristics that would make one of these sing (there was a build up of a 305 with these heads in engine masters mag last year, made lots of power) and they save alot of weight on the engine.
The Vortec's are also still on offer for the postage, however they need a rebuild (as any heads will) the bits for the rebuild arn't expensive, you can get an overhaul set of valves, spring and retainers for these heads are about £150 imported to your door. http://cgi.ebay.com/ebaymotors/SMALL-BO ... enameZWDVW
Plus you need new guide inserts and the spring seats machined and the valve seats with a 3 angle job done, this shouldn't be more than £200. On carcraft.com is a description of how to flow them to give about 10% extra flow.
I would sugest you get "how to rebuild your small block chevy" by David Vizard ISBN 978-1-55788-029-1 it is a very good guide on what to do, and has alot of info on the chevy.
Good luck and keep posting
best of luck
Mike

Raw · Post by **Raw** » Fri Jan 18, 2008 9:04 am

I took a quick look last night at my options and I think that alloy heads are looking like a good option.

My budget is a bit of a concern but I feel that the cost of two alloy heads V's the restoration of whatever iron cast heads is going to use will nearly level out!

Taking into account the amount of weight I can save with the alloy heads (and maybe performance gain...?) I think they are a real runner!

What I want from this engine easy, high revving power. With the high end power, (as I have a light car) I feel that I can sacrifice some low end grunt.

I want a good compression ratio (~10:1). I am going to have the bottom end checked out by my engine builder It has flat head pistons (with slight shoulder ~5-7mm). If they are ok in the bore I will leave them but I will be doing the bearings and shells. I don't think I will go to 4 bolt mains (cost factor) but I will go with APR bolts (crank and head).

I will also fit a new high pressure oil pump and drive.

Well that's about it I think, what ye're opinions?

What kind of heads & cam would suit? Diameter exhaust?

Padraig

kiwicar · Post by **kiwicar** » Fri Jan 18, 2008 12:32 pm

Hi
the alloy heads are a good buy, AFR are good heads with good flow, Racing head services are nice heads http://www.racingheadservice.com/Inform ... ts_New.asp
and quite a bit cheeper (I bought their 235 cc inlet tract heads, bit big for a 305 though) their pro-action 180cc heads are a bargin, especially if you buy them bare (machined) and get the valves everything off ebay as bargins come up.
Once you have chosen your heads have a look at the comp cams website and choose a suitable cam (other brands are available once you have chosen the basic spec), I would look at 234 to 244 of duration at .05 lift if it is a hydraulic flat tappet cam and with the 180cc heads you should be able to use 10 to 10.5 to 1 CR (be guided by the comments on the comp cams website) a hone and a re ring might be a good idea if you are going to re use the pistons (no reason not to if they are in good condition, stick them through the dishwasher if you have one).
Best of luck.
Mike

Raw · Post by **Raw** » Fri Jan 18, 2008 2:38 pm

What are these like? They have a little less porting but half the price and got vavles. I have new springs and lifters and collets in in my heads at moment., which could be transferes over.

Any experience with these?

http://store.summitracing.com/partdetai ... toview=sku

kiwicar · Post by **kiwicar** » Fri Jan 18, 2008 4:52 pm

The 356 casting I think is a Vortce casting (I will check when I get home) But coppied in ally, if so they are a good head, can be simply ported out later if you want, they are cheep as all the manufacturer needs to do is make the pattern and cast them no R&D costs.
If you go for a set they have limmited valve lift (this also makes me think they are vortec) and you need the right style of inlet manifold.
As a rough guide if you take the best pre vortec head from GM and port it as far as you can you may get somthing that is as good as a vortec as cast.
Sort the limmited valve lift problem and pocket port them they will be enough for about 420bhp (on a good roller cam on a street 350).
240cu ft/min should give your 305 the ability to rev to about 6500 on the right cam. These heads however are using the 2.02 inch inlets that are not a vortec size (but this might be their upgrade).
lots of people make Vortec castings in ally, have a surf on ebay (try mad dog racing or cnc motorsport or dirt track thunder)
For the chevy you can cheeply get +.1" stem valves, with the right valve springs they will solve the limited lift issue. Stick an enquiry to Summet for more info about these asking if they can build them up with longer valves and springs, they will probably not charge you much more. Some of the other suppliers may well do this as standard.
Don't rush into it yet I'll check the head casting No's when I get home.
Best of luck
Mike

kiwicar · Post by **kiwicar** » Fri Jan 18, 2008 9:02 pm

looking at things in more detail the 356 is the grade of ally not the casting number, if you go for them get a flow chart first.
These look like a good start in that they are a sensible price and have the limited lift sorted http://cgi.ebay.com/ebaymotors/Chevy-SB ... enameZWDVW
the chambers are vortec shape, no flow figures but 190 cc inlet ports make me think they are a opened out version of the vortec, but with old style inlet faces.
this seller has them bare, but has a set of flow figures fo them
http://cgi.ebay.com/ebaymotors/CYLINDER ... enameZWDVW
they seem to flow well, they crop up on a few discussion boards and seem to be OK, they are Australian, so the 'merkins are reluctent to buy them (considering most of their "made in america" stuff is infact made in china and finnish machined in the states this is a little ironic). the RHS stuff is infact from New Zealand and were dirt cheep until they got an american distrinutor who then put them in american boxes and stuck "made in america on them)
Keep hunting you can find some bargins out there (summit tend to be a bit more expensive than alot of smaller retailers.

kiwicar · Post by **kiwicar** » Fri Jan 18, 2008 9:24 pm

I would start having a think about cam before you choose your heads, the two have to match to work properly, no point buying heads that flow best at .6" lift but badly at .2" lift if your cam only open the valves .45" at max lift.
http://www.compcams.com/technical/Catal ... 26-227.pdf
is comp cams online calatog and worth a look.
What sort of block/ lifters are they, flat tappet or roller? can you post a photo of the lifter valley as you may have a flat tappet cam in a later roller lifter block (there are 4 bosses in the middle of the Valley that take the retainer for the roller lifters.
Mike

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